Responses of Lumholtz's tree-kangaroo (Dendrolagus lumholtzi) to loss of habitat within a tropical rainforest fragment

A key challenge for wildlife biologists is to predict how fauna will respon d to habitat loss. During an ongoing study of habitat use by Lumholtz's tre e-kangaroos (Dendrolagus lumholtzi), an unexpected opportunity arose to stu dy the responses of this rare arboreal marsupial to habitat disruption. The study took place on the Atherton Tableland in north Queensland: Australia, when half of a 20-ha rainforest fragment was unexpectedly clearfelled by t he landowner. Prior to clearing, six animals had been fitted with radio-col lars to monitor their locations and activity within the fragment. Most anim als responded to clearing by remaining in trees until just before they were felled. Animals then fled for short distances (mean = 33 m), but returned to their home ranges within 12-24 h. Nine additional resident animals were captured after forest clearing and radiocollared, and along with the origin al animals were tracked at ca. 12-h intervals for several months. Si?; fema les and five males directly affected by clearing continued to use their ori ginal home ranges, amongst the 1-2 m-tall tangles of woody debris. Contrary to expectations, animals did not relocate to nearby forest blocks, and onl y one animal established a completely new home range. Mortality rates of af fected animals appeared to increase after clearfelling, with at least four perishing from attacks by domestic dogs or dingoes. Although some surviving tree-kangaroos lived within the debris for several months, their prospects for long-term survival were poor as the debris was eventually burnt to cre ate cattle pasture, destroying the already modified habitat and leaving the m vulnerable to predators. The remarkably strong site-tenacity of this spec ies suggests that habitat availability will be critically limiting to their populations, and that displaced animals will have limited prospects for su rvival. (C) 1999 Elsevier Science Ltd. All rights reserved.